Channel screeds are generally known in the art and can be used, for example, in the construction of wall surfaces and the like for attaching molding or other trimmings. Such conventional channel screeds can also be used for aesthetic purposes in wall surfaces/structures, such as for providing an aesthetic partitioning in a wall covered with plaster, cement, concrete, mortar, stucco, EIFS (Exterior Insulation and Finishing System), or drywall.
Conventional channel screeds comprise a single member construction having a channel configuration defined by a base and opposed side walls extending a distance in perpendicular fashion from the base. The side walls extend a length from the base that is calculated to provide a desired depth or thickness of the surrounding wall surface material. The channel screed is attached to an underlying wall structure, e.g., a framing member or the like, by fasteners that extend through flanges projecting outwardly away from the base.
Once the channel screed is attached to the wall structure, the wall surface material is applied to the wall structure and is built up in one or more multiples of steps, to a thickness that is approximately that of the side walls. Once the wall surface material is dried, the channel screed operates to provide a desired partition in the wall structure, which can be functional or decorative.
However, several issues are known to exist with such conventional channel screeds when used in this manner. The process of building up a wall surface using concrete or other wall surface material is a messy process requiring that one or more steps be implemented during the process to keep the exposed surface of the channel screed clean or protected, e.g., by masking or other similar task. Typically, such precautions are not taken or not implemented correctly because of the extra effort and time involved in doing so at the job site. As a result, the exposed surface of the channel screed very often becomes stained and/or scratched or otherwise damaged during the process of building the wall surface, impairing or ruining its desired use as an aesthetic element in the wall structure.
Another issue known to exist with the use of such conventional channel screeds is the formation of cracks that develop in the wall surface adjacent the channel screed. The cracks result during the process of the wall surface drying and contracting adjacent to the relatively immobile channel screed. The presence of the cracks in the wall surface both detracts from the intended purpose of the channel screed, to aesthetically enhance the wall surface, and operates to provide unwanted water intrusion paths into the wall system and underlying wall structure.
A further issue known to exist with the use of such conventional channels creeds relates to the manner in which the channel screed is attached to the underlying wall structure. Typically, two or more fasteners are used to attach the channel screed to the wall structure and extend through one or more flanges projecting from the base and into the wall structure. The presence of such fasteners operates to provide a path for water to enter or intrude into the wall structure. Such water intrusion is unwanted as it can cause damage to the underlying wall system. Further, the presence of such flanges operates to cause cracks to develop within the wall structure, and also operates as a leak path for unwanted water intrusion into the wall structure.
It is therefore desired that a channel screed be constructed to facilitate its use as an element in a wall surface in a manner that preserves its external finish to provide a desired aesthetic effect, and do so in a manner that is not time or labor intensive in the field. It is desired that the channel screed be constructed in a manner that minimizes the formation of cracks in the wall surface and/or that covers the presence of such cracks from observation when viewing the wall surface. It is further desired that the channel screed to be constructed in a manner that reduces the possible water intrusion paths into the wall structure or system, thereby operating to minimize unwanted water damage.